This invention relates to bridges for string instruments, particularly bridges providing for adjustment of string height and of string intonation, while optimizing sustain characteristics of the musical instrument.
String instruments, such as electric and acoustic guitars, use bridges in establishing the intonation and height of each string. In that use, the sound and performance of the instrument depends on proper fit and adjustment of the bridge. Typically, a bridge is fitted to a string instrument and adjusted, together with the strings, in the manufacturing stage or otherwise prior to sale to the musician. The heights of the strings ideally are adjusted so that, in playing the instrument, the strings are readily and comfortably manipulated, but cannot incidentally contact other parts of the instrument. In a guitar, for example, if a string is too close to the guitar's fretted finger board, the string will produce an undesirable buzz as it makes incidental contact with one or more of the frets. In that case, improper string height detracts from the instrument's sound. On the other hand, if the string is too high, the action of the guitar suffers, as the musician must move the strings an excessive distance to reach the fingerboard. In that case, improper string height detracts from the instrument's performance. In both cases, the musician's pleasure in playing the instrument is impaired and, in turn, the musician's performance is likely to suffer.
Even if the bridge is properly fitted and adjusted in the manufacturing stage, it is generally desirable for the musician thereafter to be able to adjust the bridge so as to adjust the height and intonation of each string. For example, a musician may need or want to adjust string height after modifying the instrument, such as by replacing the strings with strings of different gauge or type, or in response to the musician's increased skills, changed playing style or otherwise. In turn, the musician may need or want to change the intonation of one or more strings, that change being accomplished by adjusting the point on the string at which it is seated on the bridge.
While such adjustability is desirable, it is also generally desirable for the musician to be able to so adjust each string independently of the other strings and to be able to make height adjustments substantially separately from intonation adjustments for any one string. Moreover, it is highly desirable to be able to so adjust each string without otherwise negatively affecting the sound and performance of the instrument. In particular, it is highly desirable to provide such adjustability while optimizing the sustain characteristics of the instrument.
Conventional bridges have provided various means for adjusting string height and intonation. These conventional bridges, however, each have significant limitations. In one conventional form, for example, the bridge is mounted on the body of the musical instrument using a screw at either side, while employing a thumb nut or similar element on each screw to permit raising or lowering of the entire bridge. An example of this conventional bridge form is shown in Scherer U.S. Pat. No. 3,396,284.
This conventional bridge form suffers from serious drawbacks, including that adjustment is only operative for raising or lowering all of the strings, rather than being adapted to adjust individually the height of each string. In addition, uniform height for all strings, when desired, can be difficult to attain due to difficulty in adjusting the screws at either side of the bridge. Moreover, while this bridge form provides for string height adjustment, its use adversely affects the sound and performance of the instrument, in particular as to the instrument's sustain characteristics. The sustain characteristics are adversely affected because the contact between the bridge and the body of the instrument is made only by the two screws, the contact being inadequate to sustain string vibration.
Another conventional bridge form overcomes some of the problems indicated above by providing separate adjustment for each bridge saddle. Examples of this conventional bridge form are shown in Shaw et al. U.S. Pat. No. 4,385,543 and Wadatsu U.S. Pat. No. 4,649,789. However, bridges following this second conventional form are also subject to significant limitations, including by adversely affecting the sound and performance of the instruments, again particularly as to sustain characteristics. For example, sustain characteristics are adversely affected because contact between the bridge and the body of the instrument generally is limited to the end of one or more screws. In addition, bridges of this second conventional form tend to suffer from complexity in design making them difficult to use in adjusting the height or intonation of the strings, as well as increasing the possibility for improper adjustment which, in turn, adversely affects the sound and performance of the instrument.
Because conventional forms of adjustable bridges for string instruments have inherent limitations, a need exists for an improved adjustable bridge.